BULK ACOUSTIC WAVE RESONATOR

摘要

PURPOSE: A volume acoustic resonator is provided to control electro-acoustic coupling coefficients by using capacitance generated between a volume acoustic resonating part and a ground plane. CONSTITUTION: An anti-resonance frequency changing part(120) is located at a fixed distance from a volume acoustic resonating part(110). The volume acoustic resonating part includes a first electrode(210), a piezoelectric layer(220), and a second electrode(230). The anti-resonance frequency changing part includes ground planes(241,251), a piezoelectric layer, and ground planes(243,253). Fringe capacitance is generated between the fringe of the first electrode and the fringe of the second electrode. The ground planes are formed in a shape symmetrical to the first electrode.